Counterflow furnace



Feb. 10, 1931. v. A. HAlN 1,792,423

COUNTERFLOW FURNACE Filed April 16, 1928 2 Sheets-Sheet 1 Fly! . INVENTQR. W ma a g j BY 17m A TTORNEYS.

Feb. 10, 1931.

V. A. HAHN COUNTERFLOW FURNACE Filed Ap il l6, 1928 2 Sheets-Sheet 2 INVENTOR [(221 a. Maw-4 BY A A TTORNEYS.

Patented Feb. 10, 1931 UNITED STATES PATENT .oFFICE vnrr A. new, or cnrcneo, ILLINOIS, AssIe oa r enoaqn na a m COMPANY, OF PITTSBURGH, PENNSYLVANIA, A oonroRATroN orrn NsYLvA IA GOUNTERFLOW EURNAQE Application filed April 16,

This invention relates to improvements in furnaces of the type known as counter-flow heating furnaces wherein cold material to be heated is conducted to a heating chamber through a regenerative chamber wherein it is preheated by the hot material leaving the heating chamber. The hot and cold materials are arranged in alternate rows and heat is transferred from the hot to the cold mate- 19 rial mainly by radiation.

I have observed that the transfer'of heat from the hot material to the cold material becomes very much less when the temperature of the hot material drops to around 900 F.

and the efiiciency of heat transfer is further decreased by the difierences in temperature of various portions of the regenerative chamber.

I have discovered that a very highly efficient exchange of heat can be effected between the hot and the cold articles passing through the regenerative chamber, by forced circulation of air in the regenerative chamber of the furnace. By this means heat is transferred from the hot articles by convection as well as by radiation resulting in a much more elficient heat transfer, particularly at the lower temperatures that may exist in the regenerative chamber.

It is accordingly one of the principal objects of this invention to provide for'forced circulation of air in the regenerative chamber of counter-flow heating furnaces, and it is a further object to provide simple and efiiclent means for producing forced circulation in an inexpensive manner. 7

In the accompanying drawings constituting a part hereof, and in which like reference characters designate like parts, Fig. 1 1s a sectional elevational view taken transversely of a furnace structure embodying the prlnciples of my invention and Flg. 2 1s a longitudinal cross-sectional view illustrating a modified form of the invention.

Referring to Fig. 2 of the drawings, the furnace structure therein illustrated comprises the usual base, roof and side wall structure of suitable refractory materials such as fire-clay brick, forming a regenerative cham- 50 her 1 and a heating chamber 2, the regener- 1928. Serial No. 270,230.

be passed through the furnace in any suitable manner, but in the embodiment shown it is charged in boxes 5 which are movable by pushing them on skid-rails 6 that are supported on brick piers Or the material may be moved through the furnace in any other suitable manner. The boxes 5 on the right hand side ofthe drawings as viewed in Fig. 1, con tam the cold charge and are movable in the direction of the heating chamber and the boxeson the. left hand side of the drawing contain-the hot material which is passing out ofthe heating chamber.

As the cold and heated charges move in oppositedirections and pass each other in the regenerative chamber 1, an exchange ofheat from the hot to the cold material is effected by radiation. As previously stated, theheatexchange is very low due to the retarded radiation at low temperatures existing. in somejparts of the regenerative chamber.

In accordance with the objects of the invention, I provide forced circulation of air in the regenerative chamber for the purpose of more completely and rapidly transferring heat from the hot material to the cold by convectionas well as by radiation and for the purpose of getting a more uniform heating by regeneration I accomplish this by the following mechanism :-As shown in Fig. 2, one or more fans 10 are suspended below the arch 11 of the furnace by means of shafts 12 which are disposed through openings 13 in the furnace roof. The shafts may be motor driven or connected by suitable belting to a drive pulley for the purpose of actuating the fans to agitate orcirculate the air in chamber 1. A plurality of such fans may be employed as shown in Fig. 2 on the cold side of the regenerative furnace, that is, the side on which the cold material is passing to the heating,

chamber 2 through the regenerative chamher 1.

As shown in Figs. 1 and 2 of the drawings the boxes 5 are supported on the skid rails a suitable distance from the floor or hearth of chamber 1 to provide space for the circulation of air whereby maximum contact of the air with the boxes containing the heated and cold articles is provided.

In the modification shown in Fig. 1, one or more fans 15 are mounted for rotation on shafts 16 in recesses 17 formed in the side wall of the furnace. The fans are located below the material as shown, and forced circulation is set up underneath boxes 5 through the piers 7 and over the boxes undenieath the arch 11. A partition member 18 is provided between the rows of boxes to aid in directing circulation around the boxes.

By the methods shown in Figs. 1 and 2 of the drawings, a highly efficient exchange of heat is produced in a regenerative chamber of moderate size and the maximum amount of heat is transferred from the hot material.

It is of course obvious to those skilled in the art that various modifications may be made in the details of construction such as in the design and arrangement of the fan elements and the furnace structure without departing from the principles herein set forth.

I claim:

In a heating furnace an elongated heat exchange chamber parallel tracks extending longitudinally of the chamber for supporting rows of articles being passed in opposite directions through the chamber, a horizontally disposed partition between the rows of articles and a fan disposed within said chamber and in position to direct air currents transversely of the chamber.

In testimony whereof, I have hereunto set my hand.

VEIT A. HAIN. 

